X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fgnulib.texi;h=b59306ff7bd4fabcf97e4d1ca8aad52275ceb5c7;hb=2a040786f2832f9bca07957be08e2870c6fd4c9d;hp=966560d595aa52f9714e3a9e102a838adaf312f1;hpb=56d0462c364d5b8ff30f30fa6a29c28b3712d383;p=pspp

diff --git a/doc/gnulib.texi b/doc/gnulib.texi
index 966560d595..b59306ff7b 100644
--- a/doc/gnulib.texi
+++ b/doc/gnulib.texi
@@ -396,6 +396,15 @@ Tests modules can depend on non-tests modules.  Non-tests modules should not
 depend on tests modules. (Recall that tests modules are built in a separate
 directory.)
 
+Each listed required module may be declared a conditional dependency.  This
+is indicated by placing the condition for the dependency on the same line,
+enclosed in brackets, after the name of the required module.  The condition
+is a shell expression that is run after the module's @code{configure.ac}
+statements.  For example:
+@smallexample
+strtoull   [test $ac_cv_func_strtoumax = no]
+@end smallexample
+
 @item configure.ac-early
 This field contains @file{configure.ac} stuff (Autoconf macro invocations and
 shell statements) that are logically placed early in the @file{configure.ac}